/* ── Breadcrumb ── */
    .breadcrumb-bar { background:#0d0d14; border-bottom:1px solid #1e1e2e; padding:10px 20px; font-size:0.8rem; color:#6b7280; }
    .breadcrumb-bar a { color:#7c5ff5; text-decoration:none; }
    .breadcrumb-bar a:hover { text-decoration:underline; }

    /* ── Page Layout ── */
    .page-wrap { max-width:1200px; margin:0 auto; padding:32px 16px 60px; display:grid; grid-template-columns:1fr 268px; gap:24px; align-items:start; }
    .page-title { font-size:1.45rem; font-weight:700; color:#fff; margin:0 0 4px; line-height:1.2; }
    .page-subtitle { font-size:0.875rem; color:#6b7280; margin:0 0 20px; }
    .card-dark { background:#13131f; border:1px solid #1e1e2e; border-radius:12px; padding:22px; margin-bottom:18px; }

    /* ── Sidebar ── */
    .sidebar { display:flex; flex-direction:column; gap:14px; }
    .sidebar-card { background:#13131f; border:1px solid #1e1e2e; border-radius:12px; padding:16px 18px; }
    .sidebar-title { font-size:0.78rem; font-weight:700; color:#9ca3af; text-transform:uppercase; letter-spacing:.07em; margin-bottom:12px; }
    .related-item { display:flex; align-items:center; gap:12px; padding:9px 0; text-decoration:none; border-bottom:1px solid #1a1a2a; transition:opacity .14s; }
    .related-item:last-child { border-bottom:none; padding-bottom:0; }
    .related-item:hover { opacity:.8; }
    .related-icon { width:32px; height:32px; border-radius:8px; display:flex; align-items:center; justify-content:center; font-size:15px; flex-shrink:0; }
    .related-name { font-size:0.82rem; font-weight:600; color:#e2e4ec; }
    .related-desc { font-size:0.74rem; color:#6b7280; margin-top:1px; }
    .tip-row { display:flex; gap:8px; margin-bottom:9px; align-items:flex-start; }
    .tip-dot { width:6px; height:6px; border-radius:50%; background:#7c5ff5; flex-shrink:0; margin-top:5px; }
    .tip-text { font-size:0.8rem; color:#6b7280; line-height:1.55; }
    .tip-text strong { color:#9ca3af; }

    /* ── Calculator Display ── */
    .calc-display {
      background:#0a0a11;
      border:1px solid #1a1a28;
      border-radius:10px;
      padding:14px 18px;
      margin-bottom:14px;
      min-height:88px;
      display:flex;
      flex-direction:column;
      align-items:flex-end;
      justify-content:flex-end;
      position:relative;
    }
    .calc-mode-row {
      position:absolute;
      top:10px;
      left:14px;
      display:flex;
      gap:6px;
      align-items:center;
    }
    .mode-pill {
      font-size:0.65rem;
      font-weight:700;
      padding:2px 7px;
      border-radius:5px;
      background:rgba(124,95,245,.15);
      color:#7c5ff5;
      border:1px solid rgba(124,95,245,.25);
      letter-spacing:.06em;
      text-transform:uppercase;
    }
    .mode-pill.second-on { background:rgba(236,72,153,.15); color:#ec4899; border-color:rgba(236,72,153,.3); }
    .mode-pill.mem-on { background:rgba(74,222,128,.1); color:#4ade80; border-color:rgba(74,222,128,.2); }
    .calc-expr {
      font-size:0.82rem;
      color:#4b5563;
      min-height:18px;
      word-break:break-all;
      text-align:right;
    }
    .calc-main {
      font-size:2rem;
      font-weight:700;
      color:#e2e4ec;
      word-break:break-all;
      text-align:right;
      line-height:1.2;
      margin-top:4px;
      letter-spacing:-0.5px;
      transition:color .15s;
    }
    .calc-main.error { color:#f87171; font-size:1.4rem; }

    /* ── Button Grid ── */
    .calc-controls {
      display:flex;
      gap:8px;
      align-items:center;
      margin-bottom:10px;
      flex-wrap:wrap;
    }
    .btn-mode-toggle {
      flex:1;
      padding:7px 0;
      border-radius:8px;
      font-size:0.78rem;
      font-weight:700;
      border:1px solid #2a2a40;
      background:#0d0d14;
      color:#9ca3af;
      cursor:pointer;
      transition:all .14s;
      text-align:center;
    }
    .btn-mode-toggle.active { background:rgba(124,95,245,.18); color:#7c5ff5; border-color:rgba(124,95,245,.35); }
    .btn-2nd {
      padding:7px 16px;
      border-radius:8px;
      font-size:0.78rem;
      font-weight:700;
      border:1px solid #2a2a40;
      background:#0d0d14;
      color:#9ca3af;
      cursor:pointer;
      transition:all .14s;
    }
    .btn-2nd.active { background:rgba(236,72,153,.15); color:#ec4899; border-color:rgba(236,72,153,.3); }

    .calc-grid {
      display:grid;
      gap:6px;
    }
    .calc-grid-sci {
      grid-template-columns:repeat(5,1fr);
      margin-bottom:0;
    }
    .calc-grid-main {
      grid-template-columns:repeat(5,1fr) repeat(4,1fr);
    }
    .calc-full-grid {
      display:grid;
      grid-template-columns:repeat(5,1fr) repeat(4,1fr);
      gap:6px;
    }

    /* ── Buttons ── */
    .cb {
      padding:12px 4px;
      border-radius:8px;
      font-size:0.82rem;
      font-weight:600;
      border:none;
      cursor:pointer;
      transition:transform .08s, opacity .1s, background .1s;
      text-align:center;
      white-space:nowrap;
      line-height:1.2;
      user-select:none;
      -webkit-user-select:none;
    }
    .cb:active { transform:scale(.93); }
    .cb:hover { opacity:.85; }

    /* Button types */
    .cb-sci    { background:#1a1a2c; color:#9ca3af; border:1px solid #23233a; }
    .cb-sci:hover { background:#22223a; color:#e2e4ec; }
    .cb-sci.active-2nd { background:rgba(236,72,153,.15); color:#ec4899; border-color:rgba(236,72,153,.28); }

    .cb-num    { background:#16161f; color:#e2e4ec; border:1px solid #1e1e2e; font-size:1rem; }
    .cb-num:hover { background:#1c1c2c; }

    .cb-op     { background:#22223a; color:#a78bfa; border:1px solid #2c2c48; font-size:1rem; font-weight:700; }
    .cb-op:hover { background:#2a2a48; }

    .cb-eq     { background:linear-gradient(135deg,#7c5ff5,#ec4899); color:#fff; border:none; font-size:1.1rem; font-weight:700; box-shadow:0 2px 10px rgba(124,95,245,.35); }
    .cb-eq:hover { opacity:.92; }

    .cb-clear  { background:#2a1a1a; color:#f87171; border:1px solid #3a1e1e; font-weight:700; }
    .cb-clear:hover { background:#3a2020; }

    .cb-action { background:#1c1a2c; color:#c4b5fd; border:1px solid #28263a; }
    .cb-action:hover { background:#242240; }

    .cb-mem    { background:#111120; color:#6b7280; border:1px solid #1e1e2e; font-size:0.72rem; font-weight:700; }
    .cb-mem.lit { color:#4ade80; }
    .cb-mem:hover { background:#18182a; }

    /* ── Result card ── */
    .result-box-row { display:grid; grid-template-columns:1fr 1fr; gap:10px; margin-top:2px; }
    .result-box { background:#0a0a11; border:1px solid #1a1a28; border-radius:8px; padding:12px 14px; }
    .result-box-label { font-size:0.7rem; font-weight:700; color:#4b5563; text-transform:uppercase; letter-spacing:.06em; margin-bottom:4px; }
    .result-box-val { font-size:0.95rem; font-weight:700; color:#e2e4ec; word-break:break-all; }

    /* ── Blog / FAQ ── */
    .blog-section { max-width:1200px; margin:0 auto; padding:0 16px 72px; }
    .blog-section-header { display:flex; align-items:center; gap:12px; margin-bottom:28px; }
    .blog-section-badge { font-size:0.68rem; font-weight:700; color:#7c5ff5; text-transform:uppercase; letter-spacing:.1em; background:rgba(124,95,245,.1); border:1px solid rgba(124,95,245,.22); border-radius:20px; padding:4px 12px; }
    .blog-section-title { font-size:1.2rem; font-weight:700; color:#fff; margin:0; }
    .blog-intro { background:#13131f; border:1px solid #1e1e2e; border-radius:12px; padding:22px 24px; margin-bottom:24px; font-size:0.9rem; color:#9ca3af; line-height:1.75; }
    .blog-intro strong { color:#e2e4ec; }
    .blog-intro p { margin:0 0 12px; }
    .blog-intro p:last-child { margin-bottom:0; }
    .blog-grid { display:grid; grid-template-columns:1fr 1fr; gap:16px; margin-bottom:24px; }
    .blog-card { background:#13131f; border:1px solid #1e1e2e; border-radius:12px; padding:20px 22px; }
    .blog-card-icon { width:36px; height:36px; border-radius:9px; background:rgba(124,95,245,.13); border:1px solid rgba(124,95,245,.2); display:flex; align-items:center; justify-content:center; font-size:17px; margin-bottom:13px; }
    .blog-card h3 { font-size:0.92rem; font-weight:700; color:#fff; margin:0 0 8px; }
    .blog-card p { font-size:0.82rem; color:#6b7280; line-height:1.7; margin:0; }

    /* FAQ */
    .faq-item { background:#13131f; border:1px solid #1e1e2e; border-radius:10px; margin-bottom:8px; cursor:pointer; overflow:hidden; transition:border-color .15s; }
    .faq-item:hover { border-color:#2c2c42; }
    .faq-item.open { border-color:#2c2c42; }
    .faq-q { display:flex; align-items:center; justify-content:space-between; padding:15px 18px; gap:12px; }
    .faq-q-text { font-size:0.88rem; font-weight:600; color:#e2e4ec; }
    .faq-chevron { width:18px; height:18px; color:#7c5ff5; flex-shrink:0; transition:transform .2s; }
    .faq-item.open .faq-chevron { transform:rotate(180deg); }
    .faq-a { max-height:0; overflow:hidden; transition:max-height .3s ease; }
    .faq-a-inner { padding:0 18px 15px; font-size:0.84rem; color:#6b7280; line-height:1.75; border-top:1px solid #1e1e2e; padding-top:13px; }
    .faq-item.open .faq-a { max-height:400px; }
    .faq-a-inner strong { color:#9ca3af; }

    /* ── Share Bar ── */
    .share-bar { max-width:1200px; margin:0 auto; padding:0 16px 48px; }
    .share-inner { background:#13131f; border:1px solid #1e1e2e; border-radius:12px; padding:20px 24px; display:flex; align-items:center; justify-content:space-between; gap:16px; flex-wrap:wrap; }
    .share-text-wrap { display:flex; flex-direction:column; gap:2px; }
    .share-heading { font-size:0.88rem; font-weight:700; color:#e2e4ec; }
    .share-sub { font-size:0.76rem; color:#6b7280; }
    .share-btns { display:flex; gap:8px; flex-wrap:wrap; }
    .share-btn { display:inline-flex; align-items:center; gap:7px; padding:9px 16px; border-radius:8px; font-size:0.82rem; font-weight:700; text-decoration:none; border:none; cursor:pointer; transition:opacity .15s,transform .12s; white-space:nowrap; }
    .share-btn:hover { opacity:.88; transform:translateY(-1px); }
    .share-btn-tw  { background:#000; color:#fff; }
    .share-btn-fb  { background:#1877f2; color:#fff; }
    .share-btn-wa  { background:#25d366; color:#fff; }
    .share-btn svg { width:15px; height:15px; fill:currentColor; flex-shrink:0; }

    /* ── Footer ── */
    .site-footer { text-align:center; padding:24px 16px; font-size:0.8rem; color:#4b5563; border-top:1px solid #1e1e2e; background:#0d0d14; }
    .footer-links { display:flex; justify-content:center; gap:20px; margin-top:8px; flex-wrap:wrap; }
    .footer-links a { color:#4b5563; text-decoration:none; font-size:0.78rem; transition:color .14s; }
    .footer-links a:hover { color:#9ca3af; }

    /* ── Responsive ── */
    @media (max-width:900px) {
      .page-wrap { grid-template-columns:1fr; }
      .sidebar { display:grid; grid-template-columns:1fr 1fr; gap:14px; }
      .sidebar-card { margin-bottom:0; }
      .blog-grid { grid-template-columns:1fr; }
    }
    @media (max-width:700px) {
      .nav-links { display:none; }
      .hamburger { display:flex; }
      .page-wrap { padding:20px 14px 48px; }
      .page-title { font-size:1.2rem; }
      .blog-section { padding:0 14px 56px; }
      .calc-main { font-size:1.6rem; }
    }
    @media (max-width:580px) {
      .sidebar { grid-template-columns:1fr; }
      .calc-full-grid { grid-template-columns:repeat(5,1fr) repeat(4,1fr); gap:4px; }
      .cb { padding:10px 2px; font-size:0.72rem; border-radius:6px; }
      .cb-num { font-size:0.88rem; }
      .result-box-row { grid-template-columns:1fr; }
    }
    @media (max-width:440px) {
      .calc-full-grid { gap:3px; }
      .cb { padding:9px 1px; font-size:0.66rem; }
      .cb-num { font-size:0.82rem; }
      .calc-main { font-size:1.4rem; }
    }